Figure 4: A screen shot from a chunk version of an e-Proof for the product rule for continuous functions

Figure 4

The accompanying audio for this screen says:

In the third chunk, we set up an overall delta value, and put together the information from the second chunk to show that if the modulus of x minus a is less than this delta, then our original modulus expression is less than epsilon.
Alcock, L., Wilkinson, N. (2011) e-Proofs: Design of a Resource to Support Proof Comprehension in Mathematics. Educational Designer, 1(4).
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